Applying the KISS to COTS
To simplify this for those who find many sequential words and developed arguments too challenging (icw the Sunday comics), I'll provide this simpler explanation.
1. TTTech and Nord Micro tried to pull a fast one by pressing into service a COTS program (Commercial Off The Shelf). Unfortunately that program, although used in many surface transport systems that have nothing to do with pressurization, had known bugs in it.
2. Even without the known bugs, OPS software that is required to drive critical systems, cannot be reverse engineered and cannot be COTS. It must be built up and certified module by module. Them's the rules and it makes Level A software expensive. Short-cutting that process can be very remunerative. We're talking tens of millions here.
3. Once the COTS genie was out of the box, and they became aware of the fraud, Airbus had to pull a quick cover-up and shut Mangan up. They, together with TTTech and Nord-Micro used the very utilitarian Austrian legal system and some compliant Judges to do just that. There's no protection for whistle-blowers in Europe.
4. They also had to start developing the bona fide article. Unfortunately that process takes six months at least (funny how the A380 got delayed by just that amount of time - yet it has been blamed upon JIT imbuggerances during customization of a/c for individual customers). That's a real weak pretext - but they had to think fast and just couldn't afford to admit that they'd been hoodwinked.
5. The possibility of all four outflow valves opening at 41,000 feet is there, mainly because the same software drives the CPCS and all facets of it. It would lead to a rapid depressurization and it would be a clear and present danger (akin to Helios flt 522)....... particularly as some failure modes are latent.
6. Of equal concern are the other airplane types flying around now with the same bogus and fraudulently COTS software. If you're interested, the types are identified by Mangan on his website.